Treatment of cellulose esters



Patented Jan. 16, 1934 1,943,377 TREATMENT or CELLULOSE ESTERS George Holland Ellis,

Spondon, near Derby,

England, assignor to Celanese Corporation of America, a corporation of America No Drawing. Application December 21, 1928,

Serial No. 327,759, and in Great Britain January so, 192

-7 Claims. This invention relates to the production of :effects (photographic or otherwise) on fabrics, films or other materials made of or containing 7 sicellulose acetate or other cellulose esters, for ex- 5. ample cellulose formate, propionate or butyrate.

g I have found that the extraordinary ease with which amines may be incorporated in cellulose ester materials enables the known light-sensi- ;tivity of diazo compounds to be utilized to ob- 10 -,tain upon such materials successful photographic .or pattern effects which are exceedingly fast to washing and which, by a suitable choice of com- ;ponents may be very fast to other agencies. Moreover the prints or impressions are not merely superficial.

According to the present invention therefore materials comprising cellulose acetate or other cellulose esters and containing diazotizable amino compounds are diazotized, the materials then exposed to the action of light of locally varying intensity and the pattern or effect fixed by development with one or more components capable of converting the diazo body-into an azo compound.

The diazotizable amino compounds, which may be simple amines or aminoazo compounds'and may be coloured or not, may be incorporatedjin the fabric, film or other material by any suitable means, but are preferably applied by immersing the material in an aqueous solution or dispersion. Aqueous solutions of salts, e. g. the hydro-chlorides, may be employed or aqueous solutions of the free bases where these are suiliciently soluble. If insufiiciently soluble the amines may still be applied as free bases in aqueous dispersions obtained by any suitable means, for example by grinding (e. g. in the so-called colloid mills) in presence or absence of dispersators or protective colloids, by dissolving in a solvent and mixing the solution with water containing or not containing dispersators or protective colloids, or by pretreating the bases with suitable dispersators for'example by the methods described in prior U, S. patents to Ellis Nos. 1,618,413 and 1,618,414 of February 22, 1927, No. 1,694,413 of December 11, '1928, No. 1,716,721 of June 11, 1929, and to Ellis and Goldthorpe No. 1,690,481 of June 6, 1928, and Ellis U. S. application Serial No. 134,138 filed September 7, 1926, and Ellis and Goldthorpe U. S. application Serial No. 152,517 filed December 3, 1926.

Alternatively suitable amino bases may be applied from solution in organic solvents, for instance trichlorethylene, the solvent or solvent mixture being so chosen that it has no deleterious effect upon the cellulose ester. Again the amino bases may be incorporated in the cellulose ester solution employed to manufacture the films, filaments or other products.

subjected to diazotization to convert the amine into the diazo form, preferably under conditions so that the light is so subdued, coloured or excluded that the diazo compound is unaffected. The material is preferably then dried under these restricted light conditions and under comparatively cool or cold conditions. If the diazo compound is itself sufliciently stable or if stabilizers be employed, the dried material containing the active diazo compound may be stored for future exposure and development. The invention iiicludes these dry materials containing the stable diazo compound.

On the fabric, film or other material thus prepared a light impression may now be obtained by any suitable means, for example by direct photography of the object in the usual way by employment of any form of camera, or by employment of any form of positive or negative or stencil or other device whereby the reflected or transmitted light incident on the material is locally varied in intensity so as to yield a design or picture as required. Exposure conditions will of course vary according to the diazo compound (or mixture) employed.

After a suitable exposure the material is sub jected to the development process, the developer being applied in dispersed or other form.

The following are examples of suitable amino compounds and developers for use according to the present invention, but it is to be understood that the listing of these examples implies no limitation of the invention thereto:-

A.- Amino compounds p-Nitraniline p-Nitro-o-anisidine m-Nitro-p-toluidine m-Nitro-o-anisidine p-Chloraniline a-Naphthylamine Benzidine Dianisidine V p-Aminobenzene-azo-a-naphthylamine B. Developers a-Naphthylamine Dimethylaniline m-Phenylene diamine a-Naphthol p-Naphthol Phenol p-Oxynaphthoic acid p-Xylidine p-Naphthylamine Aminonaphthols Acetoacetic ester. I

Mixtures of organic bases and/or mixtures of developers may be employed and by employing The cellulose-ester-organic-base complex is combinations of diazo compounds which react 1'20 diflerently to light and yield different shadeswith the same or with mixed developers, wide varieties of effects are obtainable.

I! desired, the materials may previously be dyed with, or may otherwise have incorporated therein, colouring matters which resist the diazotization process and the exposure to light, or alternatively colouring matters may be applied to the materials after the process of the present invention. By this means effects or designs are obtainable on a contrasting or shading background.

The following examples are intended to illustrate theinvention, but not to limit it in any way:

Example 1 A satin fabric woven from cellulose acetate yarns is dyed" with 1% of its weight of dianisidine which has been previously dispersed by heating with five times its weight of sodium sulphorieinoleate before adding to the dyebath. The dyeing is continued for 1 hours at 80 C., after which the fabric is rinsed well in warm water and diazotized in a bath containing 2% sodium nitrite and 7% hydrochloric acid 32 Tw., calculated on the weight of fabric. After diazotizing for half an hour at room temperature the material is rinsed very well in cold water and dried. The drying, which is preferably effected on some stretching device to avoid creases in the fabric, is carried out in subdued light while maintaining the fabric fairly cool.

A piece of the dry diazotized fabric is placed in a photographic printing frame behind a transparent positive image and exposed for the neces sary time to sunlight or the carbon are, after which it is developed in a bath containing 1.5% of methaphenylene diamine, calculated on the weight of fabric. The developing bath is raised from cold to 60 C. in V hour and maintained at 60 C. for hour. The material is finally rinsed, soaped lightly and dried. A bright scarlet photograph is obtained on a very pale cream ground.

Example 2 A woven fabric composed of cellulose acetate yarns is dyed in a dyebath of volume ratio 50 to l with 2% of its weight of 2zamino-5-nitromethoxybenzene, previously solubilized by heating with five times its weight of sodium sulphoricinoleate. After dyeing for 1 hours at 80 C. the fabric is rinsed in warm water and diazotized and dried as in Example 1. It is exposed under a stencil or transparent photographic positive to sunlight or the are light for the necessary time after which it is developed in 3% of 2.3-oxynaphthoic acidycalculated on the weight of fabric, the developer having been dispersed in the dyebath by dissolving in the minimum of caustic soda, pouring into the bath containing 5% glue on the weight of goods, and carefully neutralizing with formic acid. The developing bath is raised to C. in hour and maintained at 60 C. ,5 hour, after which the print is rinsed well, soaped lightly and dried. A bright bluish red design or photograph on a buff ground is thus obtained.

Example 3 A woven fabric composed of cellulose acetate yarns is dyed as in Example 1 with 1% of its weight of dianisidine and diazotized inthe manner givena The dried diazotized fabric is exposed under a stencil or a transparent positive photographic image to sunlight or the electric arc for'the necessary time and developed in a mixture of dimethylaniline and 2.3-oxynaphthoic acid. 1.5% 2.3-oxynaphthoic acid on the weight of fabric. is dispersed as in Example 2, and 1% dimethylaniline is dispersed by heating with sodi um sulphoricinoleate beforeadding to the developing bath. The print is developed in the mixed developers, raising to 60 C. in hour and maintaining at 60 -C.. hour. It is finally rinsed, soaped lightly and dried. A purple-brown design or photograph is obtained on a. pale but! ground.

What I claim and desire to secure by Letters Patent is:-

1. Process for the production of pattern effects, comprising diazotizing a material comprising a cellulose ester containing a diazotizable amine, exposing to the action of light of locally varying intensity and .fixing the pattern by development.

2. Process for the production of pattern effects, comprising diazotizing a material comprising a cellulose ester-containing a diazotizable amine, drying, exposing to the action of light of locally varying intensity and fixing the pattern by development.

3. Process for the production of pattern effects, comprising diazotizing a material comprising cellulose acetate containing a diazotizable amine, exposing to the action of light of locally varying intensity and fixing the pattern by development.

4. Process for the production of pattern effects, comprising diazotizing a material comprising cellulose acetate containing a diazotizable amine, drying, exposing to the action of light of locally varying intensity and fixing the pattern 120 by development.

5. Process for the production of photographic eflect's, comprisingdiazotizing a material comprising cellulose acetate containing a diazotizable amine, exposing to the action of light passing 125 through a' photographic positive and fixing the photographic image by development.

6. Process for the production of pattern effects, comprising diazotizing a material comprising a cellulose ester containing a substantially colorless 'diazotizable amine, exposing tothe action of light of locally varying intensity and fixing the pattern by development.

'7. Process for the production of pattern eiiects, comprising diazotizing; a material comprising cellulose acetate containing a substantially colorless diazotizabl'e amine, drying, exposing to the action of light of locally varying intensity and fixing the pattern by development.

CERTIFIGATEDF CORRECTION. 5

12.1mm :No. 1,943, 377. January as, 1934.

' GEORGE HOLLAND ELLIS.

It is hereby certified that the State of Incorporation of the assignee in .the above numberedpatent was erroneousiy described and specified as "Amer- 'ica" whereas said State of Incorporation should have been described and spec-h ified as Delaware, as shown by the records of assignments in this office;

pge 2, iine 38, for "methaphenylene" read metaphenylene; and that the said 'jLetters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 6th day of March, A. i). 1934.

F. M. Hopkins (Seai) i Acting Commissioner oi-Paaems. 

